Losing A Wheel On Your Commute; 3-Wheelers Vie For The Open Road

We live at an interesting point in time for the technologically minded motor vehicle enthusiast, and we stand on the brink of a major directional shift in  how we imagine a car. Within ten years it’s likely that the electric motor will have moved from an extravagance or a fringe choice to a mainstream one, and a piston engine will be the preserve of an ever smaller niche market.

The Electrameccanica Solo three-wheeler car.
The Electrameccanica Solo three-wheeler car.

Along the way is it possible that the very form factor of an automobile will change, or will cars in decades hence have the same basic shape as those we’re used to? The Canadian company Electrameccanica certainly think so, because they’ve launched a refreshingly different take on commuter transport for one. Their Solo is a three-wheeler car, with two wheels at the front and one trailing wheel at the back configuration. It’s a bold design, but if it’s such an obvious one then why don’t we drive three-wheelers already?

It’s time to examine a few of the properties of a three-wheeler, and along the way visit some of the past attempts at this configuration.

There Are More Three-Wheelers Than You Realise

It’s hardly as though three-wheelers are a new phenomenon, both the world’s first motorised vehicle created by Nicolas-Joseph Cugnot in late-18th century France and Karl Benz’s 1885 first ancestor of all modern cars had leading wheel designs. Writing this in the United Kingdom the first that come to mind are the Morgan trailing wheel sports car, the Reliant and Bond series of leading wheel small cars and vans, and maybe the Grinnall Scorpion sports car as a spiritual successor to the Morgan before Morgan decided to get back in the game themselves.

The Grinnall Scorpion is a three-wheeler I would definitely drive! Brian Snelson (CC BY 2.0)
The Grinnall Scorpion is a three-wheeler I would definitely drive! Brian Snelson (CC BY 2.0)

The astonishing variety of three-wheeled machines across all conceivable vehicle types already produced will probably come as a surprise to many readers. With so many tries at the formula one might expect that more of them of them would have gained long-term traction, so just what is it about three-wheelers that lacks appeal?

It’s fair to say that humans value conformity, so it’s possible that one of the steepest barriers for a new three-wheeler is the thought of what others might think should you rock up at work in one. I would drive a Reliant Robin because it’s a quirky little motor and has the last vestige of the famous Austin 7 in its automotive heritage, and I’d love to own a Piaggio Ape because it’s the epitome of Italian small farm transport and a handy little pickup truck to boot, but I’m a farm-dwelling hackerspace denizen and not a besuited drone on the corporate ladder.

As it stands, I run a retro Volkswagen and a decrepit Triumph not through necessity but because I like them; a modern would make sense in every way possible but if I had a Ford Mondeo on the drive then something inside would have died. Perhaps many readers will join me in this sentiment, but for most people the fear of ridicule or non-conformity is a powerful motivation and a  Toyota Corolla is a much safer bet than a small-production car that’s a little bit weird.

We are however not here to pass social commentary, instead our purview lies in the technology of what we write about. If three-wheelers make practical small car transport, are there any technical reasons why they are inferior?

Is A Three-Wheeler Really Worse On Corners?

Despite the BBC’s Top Gear playing tricks with strategically-placed ballast to make fun of the Reliant three-wheelers as comically unstable, the truth was that they had no worse handling in the corners in normal driving conditions than many of their contemporaries in the 1950s through the ’70s. In an age of near-flawless-handling front wheel drive cars, it’s easy to forget that there was a time when many four-wheeled vehicles required an element of care to drive while staying on the road. My Triumph Herald certainly raises some doubts.

To gauge what happens when you push a car to the limit I had a chat with some of my friends in the kit car community. I also have my own knowledge from a youth misspent on motorcycles.

If you push a four wheeled car into a corner, the force  increases on the outside front wheel and decreases on the rear inside one as the car is both pitched forward by deceleration and put into a roll by the centripetal force of cornering. The Mini in the picture below has its rear nearside wheel off the ground, and though the body roll has reduced the force on its front nearside wheel it still retains three wheels in contact with the road. Assuming that the contact patch of the offside wheel with the road does not lose grip from the sideways force, it retains enough contact with the road for its driver to remain in control.

Looking at a leading-wheel three-wheeler such as the Reliant tackling the same corner as the Mini then, the same forces apply upon cornering. The car will experience body roll, the front suspension will be compressed, and in extreme cornering the rear nearside wheel will lift off the ground as the Mini’s has. Where it differs from the Mini though is that its single centrally-placed front wheel then becomes a pivot point. With only two points of contact between the road and the car it becomes both far more susceptible to rolling, and the friction of the tyre contact patches countering the sideways force becomes correspondingly less than the Mini with its three wheels left on the road. In normal on-road driving the car is unlikely to reach this point, so the Top Gear piece linked above resorted to subterfuge to achieve the effect.

A 1933 Morgan 3-wheeler cornering at the Nürburgring in 1976. Lothar Spurzem (CC BY-SA 2.0)
A 1933 Morgan 3-wheeler cornering at the Nürburgring in 1976. Lothar Spurzem (CC BY-SA 2.0)

A trailing-wheel three-wheeler might then be expected to be the ideal configuration, its two widely-spaced front wheels providing the stability and two contact patches on corners that the Mini has, while its single rear wheel removes the tendency in four-wheel car for a rear wheel to come off the ground in cornering. All is not so perfect though, because in heavy cornering a trailing-wheel car can experience something in common with a motorcycle.

The highside is a term familiar to motorcyclists, an accident while cornering in which the rider is thrown upwards into the air over the bike. Motorcycles counter centripetal force while cornering by leaning into the corner, the highside begins when the rear tyre contact patch with the road loses grip and the rear of the bike begins to slide sideways. Inevitably after a period of this sliding sideways it momentarily retains grip, and the sideways momentum over this new pivot point causes the bike to sharply sit upright and launch the rider into the air. Exactly the same phenomenon can occur with a trailing-wheel three-wheeler under extreme cornering, causing the car to flip up and the inside front wheel to leave the ground. Instead of the driver being flung into the air the car can roll over spectacularly, as one of the kit car folks I asked related seeing a Grinnall do once while on a trackday.

Commuting, Not Racing

Neither of these doom-laden outcomes are the result of a typical cornering manoeuvre in a three-wheel car at road speeds, and cars such as the Reliants, Grinnalls, Morgans and others cover many thousands of miles each year just as their four-wheeled equivalents do. Your community general public will spend more time in bumper-to-bump than they will ripping around the corners.

The Solo looks to be an interesting car that deserves a chance to break the automotive mould, but to avoid going the way of the Corbin Sparrow before it, there has to be something exceptional in that diminutive chassis. At least unlike the Sparrow it’s got the looks for the job.

76 thoughts on “Losing A Wheel On Your Commute; 3-Wheelers Vie For The Open Road

        1. Yeah, when they decided to make their own engine, that is when I knew it was over. Coulda just used the Geo 3cly and there would be tens of thousands of hem on the road right now. I don’t know if ‘they’ never planned on coming to market, but I’m pretty confident that they won’t be.

          1. 1. The Geo 3 cylinder engine has been out of production for 20 years and was designed more than 25 years ago.
            2. Elio does not own the rights to it, and who says Suzuki or GM would sell them?
            3. Why build an old-tech engine you don’t own that doesn’t suit your needs?

            Elio explained more than once that the Suzuki G engine wouldn’t fit the performance envelope they needed, even if they could get the rights. Elio made many, many mistakes, but choosing NOT to use the G engine was not one of them.

          2. There’s a lot of suitable in-production engines they probably could have licensed, but apparently they preferred to keep biting off more than they could chew. Also should have kept it RWD. Ah, well. Coulda woulda shoulda.

          3. Luke, there’s plenty of performance-oriented reverse trikes that are RWD, and they’re fine. So I suspect that something with economy car performance would likewise be fine.

          4. I don’t doubt they’re fine, I’m just questioning whether it’s the best idea.

            It’s usually done because they’re based on motorcycle engines, so it’s the simplest way to design it. Otherwise you’d have to re-design the gearbox to have a differential, add the U-joints, etc.

          5. agreed. there are plenty of motorcycle engines that are available that would have fit the engine compartment and would have been in the fuel consumption range to just get the things on the road. if they wanted to make their own engine, fine, but do that on a later model once you had the money i nthe bank to do that sort of thing.

          6. I was really pulling for Elio. I was planning on purchasing one once they came out, but as more time passed it seemed like it was just a money grab for pre-orders, gov-funding, and that sweet VC money.

      1. I’m just saying the article starts out with a plug of a 3 wheeler upstart that seems to me to be reminiscent of the Dale and Elio. Maybe put a little note about these things not always working out, lol.

  1. Let’s not forget Mechanix Illustrated and Popular Mechanics construction article veteran R Q Riley, with several homebuild “commuter trike” type designs…


    I was hoping he’d switch to new beetle mechanics, since there were tonnes of those around for cheap, but later stuff went with Subaru, which disappointed me, due to a local “cold spot” in Subaru availability (Was in a no dealers for miles zone until 5 years ago, which doesn’t magically manifest 15 year old ones.) I should look again at his new stuff, see if he’s got any alternatives.

  2. No mention of fuel consumption being less due to lower friction (less wheels), or perhaps higher due to 3 surfaces in the aerodynamic sense vs 4 (but 2 of them bit shielded by front wheels)?

  3. I would hope, though unlikely, the market could support an economical reverse trike, perhaps with tandem seating. My understanding is that here in the US, it would be classified as a motorcycle in most if not all states. The silly thing is, that technically, in states where helmets are mandatory, you would have to wear one while driving one of these even if the cabin is completely enclosed.

    Also, that Top Gear Reliant Robin segment is one of the best they’ve ever done, IMO. I still watch it from time to time, and it never ceases to be funny. I remember almost dying from laughter the first time I watched it when Jeremy rolled it on the very first turn right after claiming he wanted to see how far he could go without doing it. Classic.

    1. Where I’m at, in Colorado, I see a Polaris Slingshot tadpole/reverse trike out on the highway approximately every day during my commute, and two of my neighbors have them.

  4. Registering 3 wheelers in the US may vary by state, but where I am they are automatically considered motorcycles.

    Pro: you can register anything with 3 wheels, a headlight, and an engine. Tuk Tuk? No problem. And the feds regulate motorcycles much less strictly than cars – no crash testing, not much of an emissions requirement. That’s why there are many dozens or even hundreds of custom motorcycle companies but few auto manufacturers who can sell cars and trucks with new titles. Liability insurance is cheap – how much damage can a motorcycle do to someone else? Yes, I know.

    Con: you have to have a motorcycle license to drive it, and you can’t run it on the Blue Ridge Parkway or even own one in some Deed Restricted (HOA) neighborhoods. As mentioned, you have to have a helmet on, but I consider that as much a feature as a drawback. Full coverage insurance is expensive and you need to check if your life insurance will pay out in a bike wreck.

    There’s a lot more (legal) room for innovation in the 3 wheeler space.

      1. The Parkway is split in two parts near Waynesboro VA; the north and south halfs. Living along the southern half, I have taken my bike out a few times but always find I want my DSLR for a photo and don’t have the space. The northern half in VA has some toll sections and other restrictions along some parts; I would expect a “no motorcycle” section that has an easy detour.

        But Southwest VA, riding down to NC is a beautiful and occasionally tiring ride. And if you go for the Dragon’s Tail in NC . . . gods help you, cause I don’t think I have the stomach for those corners.

    1. Motorcycle emissions regulations have been getting more stringent, and not just in California, and thus have been getting equipped with catalytic converters. Not necessarily a huge deal for a small manufacturer who presumably would license some other company’s engine, but it obviously still adds to the cost. Then again, I haven’t really seen any [potential] trike manufacturer trying to make a dirt cheap product.

    2. In CA the SOLO is a motorcycle but apparently you don’t need motorcycle licence. As a practical second car for commuting with a few days of range I am looking forward to trying it.

  5. I generally consider it the wisest thing for me to do to stay off the road — I have Asperger’s, and included in that package is a lot of stuff they don’t tell you about on TV… things to do with coordination, for example. I absolutely cannot balance on a bike of any kind, motorized or not. I fall off instantly. A close friend of mine who has Asperger’s as well — but in a very different way, of course, because that’s how that works — keeps saying, “yeah there’s a gyroscopic effect, just get on it and once you’re up to speed you’ll be fine”… no I won’t, pal, my body doesn’t gyroscope. Also, I tend to zone out pretty quickly unless I’ve got something fairly interesting in front of me (traffic generally doesn’t count), fleeting sights of unusual objects will briefly snag my attention (oh hey — that’s a Tesla!), because I also have ADD, and not only are my reaction times insanely hideously slow (most of a second at bare minimum) but I also tend to panic-freeze.

    Yeah, I’m better off as passenger or pedestrian. Besides, that means when I get one of those “We’re calling you about your vehicle’s warranty” robocalls, I can play with ’em a little bit (full disclosure: I’ve never actually done that, in part because most of those folks are people so desperate to pay the bills that they’re taking that job because it’s the only legal way they have to make rent at the moment, and they don’t want to be homeless any more than most everyone else) — “Yeah, well, it’s okay, these sneakers only had about a 90-day warranty, and they’re getting a bit worn now, since I’ve had ’em for a year or so, maybe I *should* go down to Wal*Mart and get another pair…”

    …but if I *were* to take up the call of the open road…

    Ultimately, my dream vehicle would be a scratch-built three-wheeler in the tradition of a set of largely agricultural creations I’ve seen online, all of which appear to be Polish in origin — apparently, during the Communist years there, there was a particularly popular motorcycle sold under the brand ‘WSK’ (I hear they’ve since changed names and now make helicopters instead… /shrug ) and a lot of farmer types have since basically taken the engine and certain chassis parts, along with a drag-behind sort of cart like the kind you’d see behind a lawn tractor or whatever here in the US, and you know whatever else they could scrounge or bargain for or whatever, and they put it all together into these extremely unique (seriously, every photo of a different vehicle I’ve seen, has things in a completely different configuration) three-wheeled conveyances. Basically it amounts to a homebrew Piaggio Ape. The first one I saw, BTW, was in a Hooniverse article that I randomly stumbled into while looking for something entirely different — https://hooniverse.com/three-wheel-tuesday-this-awesome-pickup-truck-ish-thing/

    The amazing things that people in difficult circumstances can do with a pile of scrap materials has, for a long time, been a source of considerable admiration from me, and inspiration to me. Forgive me for sayin’, I can do a pretty decent job of it myself in certain ways, now and again, but scaring up a mini-truck from an old motorcycle and bits of long-disused farm equipment is something else entirely!

    …that said, I actually have a picture in my mind of my little scrap-built truck (and a hand-drawn picture of it with a character of mine… hey, I’m an artist, whaddaya expect?) and I can tell you each part and where it comes from and what it does — but that’s a whole article in and of itself so I’m not gonna do that here. I don’t want to be nearly so boring anyways. Suffice to say for now that it runs on a custom built, improvised, alcohol-fed Stirling engine, and the transmission is largely put together from GY6-style scooter components.

    Second choice would be a Chinese agricultural vehicle. They use the term “tuo la ji” for the thing — I’m told that translates roughly as “farm tractor” — but this is absolutely not the image most Americans would have of such a thing with that label ;) the more popular Anglicized name is “Chinese Tiller Truck”. These are about as simple as you can get and still be road-worthy. The cab is simple sheet metal, almost always painted a sort of army-ish version of forest green (I’ve seen a single photo of a blue one… the green varies somewhat, but is pretty universal… that said, there’s also a number of ‘homebrew’ versions, for which the paint scheme is of course “anything goes”!); some don’t even have windows on the doorframes. Heck, some don’t even have *doors* — think “old FedEx step van” but with a door that never shuts! Some cabs are flat-front (my favorite), some are flat except for an angled windshield, some have a curved or beveled front — but they all have a little roof rack for storing extra stuff. The back is a cargo area, like a pickup bed, of the same painted cheap steel as the rest of it (complete with rust spots, as elsewhere), but with a canvas top like you see on military cargo trucks. The inside is aescetic enough to make a Spartan feel perhaps a bit ostentatious — besides the (quite minimal) controls and instrumentation, you get an eqtremely primitive bench seat, and if you’re lucky, windshield wipers! (I’m pretty sure I’ve never seen one with even a radio or an interior fan — air conditioning or other Western ‘creature comforts’ are absolutely right out.) The part *in front* of the cab is the most unique bit, though… the engine is universally a swamp-cooled, single cylinder agricultural diesel engine, with a bright red painted fuel tank (usually doing double duty as, er, a headlight mount!) smack on top, and a belt drive off the (seemingly) massive cast-iron flywheel driving what has to be an insanely simple transmission to often a single front wheel (four-wheeled versions are increasingly common, but let’s not talk about that!) — and the whole assembly, engine, transmission, and front wheel(s) — that’s all one single unit, mounted on what has to be an incredibly strong set of bearings, because the whole thing (yes, engine, transmission, *and* wheel!) all pivots when you turn the steering wheel!

    The engine, BTW, is what gives these things their name — it’s commonly used on other Chinese farm equipment, particularly rototillers. Being a simple diesel, it may or may not be particularly efficient, depending on what you pour in the tank, but generally speaking if you can make it both pour and burn, you can use it as fuel :D from Vaseline thinned with rubbing alcohol (yikes… can you even do that? not that you’d likely want to!) to kerosene to that bottle of rancid Wesson you meant to throw out last Thanksgiving (LOL) but forgot about, so it’s still sitting at the back of the pantry…


    Apocrypha has it that the design originates in the Soviet Bloc, but I’ve only heard that once or twice, and I’ve never been able to verify it one way or the other — for now I’m calling that story complete BS, but I don’t actually know.

    There’s a Flickr group with a bunch of pictures at https://www.flickr.com/groups/1402935@N25/pool/ — the most recent pictures are first, and those seem to be the ‘homebrew’ versions, so scroll down a bit, please… ;) in particular, there’s a *very* good shot of the front end unit (engine, transmission, and front wheel) at https://www.flickr.com/photos/mikeheather/5109373133/in/pool-1402935@N25/ and a side-on picture of my favorite configuration at https://www.flickr.com/photos/44904157@N04/5263026444/in/pool-1402935@N25/

    The third choice that I’d have would be a Bond Bug. I dunno… there’s just something about drivng around in a very 1970s wedge of Sharp Cheddar on three wheels (no, seriously, go look it up, you’ll see what I mean) that makes me want to grin like an idiot.

    Maybe there’s something to that last bit (“…grin like an idiot.”). I dunno, I’ll leave that to the amateur psychologists on here :D

    Meh… I know I have weird tastes… goes with the rest of me ;) but hey — it’s fun to imagine, right?

    1. Don’t worry about keeping your balance. On a bicycle, just turn the handle bars in the direction you’re starting to fall. That is what keeping your balance is. The rest is a refinement of that concept.

        1. As someone also on the spectrum, I found a motorcycle to be easier than driving a car. Full 360 visibility, easily see things right in front of me, and most important is the inability to focus on anything but controlling the bike.

          Driving a car, my foot naturally figgets and my speed goes up and down without me noticing. If I try to notice, I end up watching the gauges instead of the road. On my bike, I only have the speedometer which is bright enough that my peripheral vision sees it. Then, I can hyperfocus on the road and other vehicles.

          Had a therapist once ask about why I wouldn’t drive, she said something like “from your place to my office, you can get on the interstate and just go, you have time to think and zone out.” I told her that is how cage drivers kill motorcyclists; that being on two wheels was anti-zen since I got to pay attention to everything, even spotting the reflections off car hubcaps to see if the driver was loose on the steering wheel or was planning to get into my lane without seeing me.

          We all have our preferences and abilities. Walking would be great, but long term damage to my spine not treated with any pain meds has given me a limp and uncomfortable orthopedic shoes.

          1. Yeah nope. It’s actually a little more complicated than I explained previously. When I say “I can’t balance” — what I mean is, it is very easy for me, on a clean, hard, flat, not-shifting/weird/etc surface, with me perfectly sober (eg a nice residential hardwood floor, or gov’t sanctioned lowest contract bidder porcelain tile grade-school cafeteria floor) to just flat out fall on my butt, especially if I’m carrying something. I have to reduce my walking speed to about half normal (and normal is already quite slow) to carry say a full coffee mug without either (a) spilling most of the contents over myself and the floor (b) dropping the mug (c) otherwise making a remarkably amazing mess or (d) some combination of the above that manages to be even more awful somehow.

            On literally any surface that does not seem to my body to be “floor like”, it loses absolutely all internal sense of its location relative to other objects/etc in the room. You know that “oh s*** son” sinking feeling you get in you in that split second between when you realize you’re going to fall and when you actually start falling? If I’m on even the first step of a ladder, I have that sensation until I get off the freaking ladder. That’s right, it doesn’t effing stop till I get off — and the higher I go the stronger it gets. I can tame it a little (and only a little!) if I have some sort of railing to grab, which is what enables me to use stairs.

            Training myself to be able to car in *any* way took literally over a decade, and was a distinctly unpleasant process for myself and my parents… I had motion sickness with the kind of violent fervor usually confined to the sort of religious fundamentalists that cause major societal problems. When my age was in the single digits, you almost couldn’t get me into the car (never mind starting the engine or the vehicle actually *moving*, mind you!) without me horking back up at least my two previous meals, at once. My mother quickly learned to prepare for this, but she wasn’t exactly perfect… my grandmother had to have cataract surgery an hour away one time in the early 1990s, and that was a very memorable trip for Mom… she’d bribed my impossible-to-meet desire to stay home that day (she was not willing to daycare me while she worked, so she worked from home then… Dad was on a business trip that day, IIRC… or something… suffice to say he was unavailable) with my favorite breakfast… a breakfast burrito meal from McDonalds. Two burritos, a hashbrown patty, and frozen orange juice in a little foil-covered plastic cup that you stabbed with a straw to drink, hoping it wasn’t still partially frozen (it often was). Mom had brought a change of clothes for me, knowing I’d need it… but she hadn’t quite planned on needing *two* changes of clothes for me, though… and she did. I’ll let your imagination work out exactly how that went…

            It’s still kind of hard for me to do anything in a car other than sit, chat, look out the window, and listen to whatever music can be made to play… even fiddling with my phone will make me queasy, still, now, today. I’ll be 34 next month.

            A motorcycle, for me — or anything with only two wheels, such as a 50cc moped, which the friend I mentioned earlier insists would be perfect for me (nevermind that I can’t afford it — or the fact that NC now requires such things to be registered and insured, pretty much because a******s, which means I can afford it a whole lot *less*!) often sarcastically calls “DUI-mobiles” which… oh heck I’m gonna get yelled at because that’s politics these days but I don’t friggin care, a spade is a spade.

            North Carolina’s last governor was Pat McCrory, a Republican. His party ran the legislature during his tenure, and even though NC was smart enough after Duke Energy bought themselves a state (it’s not even an “open secret”, everybody talks about it, openly, as exactly what it was) so that they could swallow Progress Energy and become Duke Energy Progress (there’s absolutely nothing “progressive” about them, in *any* meaning of the word at all ever) and raise everybody’s rates (funny how they said those rates would go *down*… they didn’t, and I for one was unsurprised)… anyways, after that lovely little incident, we all figured out a Democrat up top might be a good idea after all.

            A pity that Governor Roy Cooper didn’t bring a Dem state legislature with him. I’ve been hearing all sorts of unfortunate noises about *that* tug of war.

            But during Pat McCrory’s administration, one of the things they decided to deal with was the fact that, since a moped is, in NC, not a “motor vehicle” under the law, people who get their license revoked because they’re too stupid to put the bottle down while they go out to get another bottle (or box of them!) can still drive mopeds… and a lot of DUI-revoked licensees get mopeds having not learned their lesson, and off they go injuring innocent people because they’re not only too stupid to not be drunk on the effing road, they’re too stupid to learn from their own highly traumatic mistakes that result directly from that selfsame behavior.

            So the legislature, being made of people who are largely voluntarily using an equally small portion of the otherwise-fine brilliance God (or whomever –or not– one chooses to believe in) to solve society’s problems, the balance being dedicated to exploiting the poor, downtrodden, and unfortunate in the surrounding society for their own personal and collective gain (it’s a spade, and I’m not calling it anything else), decided that the best way to deal with this was NOT to simply make it illegal to drunk-drive a moped, but instead to basically collapse the entire freaking moped market across the entire state by requiring all mopeds to be registered and for their owners to have insurance on the vehicles — mind you, *titling* is not required, nor is a licence of any kind, but the added cost and hassle of getting and keeping insurance means that there’s no advantage whatsoever to having such things, you might as well go for a motorcycle license so you can get a Chinese GY6 scooter (which is a knockoff Honda Super Cub in various overly pretty — and occasionally overly *pretentious* — guises, and often not a good one!) and get something with an engine that has more horsepower than a cheap desk fan and can handle hills taller than a speed bump.

            Way to go, guys >_< you found a cure that was worse than the initial disease, and you went out of your way to do so, when you didn't freaking have to!

        1. Yes, and I’m not surprised to hear of that — they’re all over that side of the world now… but I’m pretty sure the first ones were in India… I’d have to research it, though, and I’m not doing that right now because I’ve got other things to do that are more important and more urgent ;)

  6. We must keep in mind that the Reliant three wheelers don’t just roll like that. They were specifically prepared by the top gear producers to make them extremely easy to roll over.
    While three wheelers are less stable in general, it’s not as bad as top gear insinuates.

  7. “but for most people the fear of ridicule or non-conformity is a powerful motivation and a Toyota Corolla is a much safer bet than a small-production car that’s a little bit weird”

    I must be one of the weird ones then, I find reliability/efficiency/price to be a powerful motivator when picking a car XD

  8. Buckminster Fuller’s single-rear-wheel Dymaxion Car was famously unstable, though I don’t understand the dynamics of why.

    A three-wheel trike is much more stable with a single steering wheel instead of a single rear drive (but two rear wheels are very effective at breaking your leg when you put it down).

    I’ve seen more taildragger airplanes cartwheel than I have tricycle under carriaged ones.

    Maybe superstition, but a single rear wheel makes me nervous, even if the Can-Am looks more solid than the previous examples.

    1. Then there’s the unique approach taken by the Dutch company, Carver, on it’s trikes. Two wheels in the back, with the engine/motor “pod”, while the body and front wheel pivot/lean over it.

    2. For various reasons having to do with thrust line, brake contact patch compared to center of mass, and location of the steering wheel at the rear, taildragger aircraft have positive divergence: when the swerve starts, it increases in magnitude until you groundloop. Tadpoles with the steering at the front and the drive at the rear are not positively divergent. They under- and over-steer more like normal four wheel cars unless you manage to get into significant oversteer conditions followed by the rear wheel grabbing again. And if my local church parking lot is any guide, everyone who gets a tadpole motorcycle immediately goes out and spends four hours or until the cops show up doing burnouts and slides and in so doing learns how to handle this.

  9. The one thing all these small 3 wheeler fail at massively is being actually more useful than a similar length and width 4 wheeler. The only purpose being if your local law makes 3 wheels cheaper in some daft way.
    -Less internal space – so probably less seating and less luggage (which means it becomes a single person commuter car only so everybody probably then needs a second or third car per household to carry the kids/shopping in!)
    – Can’t do the motorcycle and zip between traffic as they are still too wide same as the 4 wheeler
    – fuel economy, range etc are all pretty comparable if keeping engines and weight etc similar. Yes most 3 wheeler are a slightly better aero shape and probably a touch lighter for the same loads. Which makes bugger all difference at normal road speeds – drag does not scale linearly with speed being pretty damn low at low speeds and ramping up hugely as you get police interesting in your driving habits. So the extra costs of needing a normal use vehicle both to make and to run outweigh the saving handily (assuming you can make do with the small 4 wheeler for all your vehicular needs and don’t need the full on 7 seater SUV etc)

    Very much a niche vehicle that for me achieves nothing much. Love the looks of the Morgan, sure they are great fun but practically they are a poor hybrid of Bike and normal car. If you really want efficient cheap single person commuter transport use a two wheeler. If you want a Practical motor vehicle for your use get a 4 wheeler – don’t waste resources having more single use vehicles than you must!

    1. The narrower chassis reduces the drag area, which reduces the drag at speed in a linear fashion.

      But engines don’t scale down well, so you lose efficiency, which diminishes the difference in fuel economy.

  10. This is probably only of interest to gearheads, but Electrameccania, who built the car in the lead picture, is a subsidiary of Intermeccania, a car company that made a range of fairly famous and competitive race and road cars from their base in Italy in the 1960’s, and then moved to California for a while and then Vancouver. Intermeccania also makes a number of replicas of classic cars, including an absolutely beautiful Porsche 356 speedster that’s electric, with far better accelleration and handling than the original, and a range of other interesting vehicles.

  11. I must have missed it in the article – why would you WANT to do three wheels? ie what is the (or any) reason you would want to do them over either 2 or 4?

    Is it cheaper? Beter control? Safer? Easier to design? More fuel economical?

    To me they seem to be the worst trade off possible, it’s hard to see any situation that either a 4 wheel, or 2 wheel, vehicle wouldn’t be better.

    1. 1: three wheels means it’s a motorcycle, so no requirement for ABS, airbags, traction control, seatbelts, lane-following, crumple zones, or a wide variety of other expensive equipment that keeps people alive.
      2: you don’t have to balance, and it has a reverse gear so you can get it out of a parking lot without having to muscle your way out.

    2. 3 wheels means motorcycle so no air bags, or ABS, etc. (as already mentioned) but also no crash testing (or pretty much any other testing)… there are way fewer hurdles to get a motorcycle to market vs a car.

      3 wheels also allows for a design that is substantially more aerodynamic, (mostly because it’s narrower) thus more efficient, thus more miles per kwh, and a smaller (cheaper) battery can give the same range as a larger (expensive) battery in a full sized car.

      So for a manufacture taking this route seems very appealing, but unless they can hit a price target that consumers are willing to make the trade off on number of wheels and perhaps licensing (Depending on the state) then they won’t actually sell any.

  12. Delta trikes aren’t nearly as stable at high cornering as a tadpole trike is.
    One cannot forget though that even though a tadpole configuration is very stable for a 3-wheeler, it suffers from one safety issue. If you brake with the rear wheel, even minutely, it makes the entire vehicle go into a dangerous fishtail wobble. On my tadpole trike (pedal driven), the rear brake was only usable as a parking brake. The rear brake was also useful if one wanted to do mad drifts :D

    Of course, locking up the rear wheels even in a four wheel configuration is also dangerous. It just cannot be omitted that this problem also exists with the three-wheeled variant.

    1. I think it’s a weakest link problem, 2 contact patches at front trumps one in the rear, for equal tire sizes. So if you went to thinner tires in the front, make the contact patch total same as rear, it’s more balanced, but then you might get understeer.

      1. It’s about where your center of mass is relative to the center of drag. When the rear wheel starts to slip sideways, the mass of the vehicle tries to overtake the front wheels.

        In a tadpole bike the driver is usually the largest mass and they’re sitting fair ways back from the front axle, or there’s an engine between the driver and the rear wheel adding more swinging mass to it. It’s common to see them built with all the mass behind the front axle, and that’s an unstable configuration.

  13. Jenny – great post.

    The advantages or a 3-wheeler is that it can have a lower frontal area and thus a better coefficient of drag – meaning more range for a given battery capacity.

    A smaller footprint on the road, and easier to park in smaller parking bays – in densely populated cities.

    Seating can either be side-by side – or in the case of the 2 seater Messerschmitt – in tandem

    Two wheels at the front is the obvious configuration – nobody is going to reinvent the Reliant Robin anytime soon.

    Three wheelers were once very popular in the UK, because they could be driven on a motorcycle licence – and not require a full car licence.

    In 1993 I was involved with an electric land speed record – for the under 500kg class – using a custom built race car, built by a group of Sussex school students in Bexhill on Sea.

    Not strictly a 3 wheeler – as it used 2 motorcycle wheels at the rear, on the same axle, on a very narrow track – which effective formed a single powered, wide, rear “wheel”

    We achieved 106.74mph at the former airbase at Greenham Common – which at that time had recently been handed back to the local Newbury Council – and benefitted from having a 3km runway.

    As this was done mostly before the popular advent of the internet – there is very little online documentation – but I did find a link to a newspaper article


    The car is now in the Bexhill Museum – and I found an online photo here


    1. In addition to the Can-Am three wheelers, I’ve also seen a few of the Polaris Slingshots out on local roads, with two side by side seats. While most of the car-like three wheelers have been vaporware so far, there’s been a definite rise locally in the number of open, motorcycle-like three wheelers on the road.

    1. You probably already know this, but those are what the aircraft company built when it wasn’t allowed to build aircraft, so it built aircraft with no wings that you could drive around town instead. Hence the design decisions. They’re kinda hair raising to drive, especially in modern traffic. I drive a tiny vintage car a lot anyway, and that’s scary enough, but the ME200 feels like driving a pram.

  14. One of the less commonly mentioned issues with 3 wheelers – – it is a lot harder to avoid potholes and speed bumps. In a 4 wheel car you have 2 ‘tracks’, a two wheel bike has just 1. But a 3 wheeler has 3 tracks. If there’s a bump in the road, you’re going to hit it.

  15. One thing no one’s mentioned about a 3 wheeler, it’s all well and good on a nice flat road, until you hit a bridle way, country path or anywhere 4 wheel vehicles have left tracks. 4 wheels use both tracks, motorcycles can use either of them, and there’s you stuck with one wheel flapping about on the bumpy in the middle.

    I believe it’s due to this problem that 3 wheeler have never really made it past being a curiosity.

  16. Jenny, I read your articles with interest and I believe Hackaday readers are not like most people: worried about conforming. If like to think we are more independent and critical thinking. Perhaps, dare I ask, since you understandably stated article purview, pen a non-hack article on the demographic or psychology of the readership?

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